During oil and gas production, it is sometimes necessary to assist the production in a well due to a high hydro-static pressure. If the well itself is not capable of generating the sufficient pressure to drive oil or gas to the surface, or the well has been deliberately killed, a tool may be used to lift the well fluid to the upper part of the well. Such tools are often referred to as artificial lift tools.
By submerging a pump tool in a well, the pump may be used to boost the pressure or perhaps restart a dead well. The pump tool forms a plug or seal in the well and pumps well fluid from one side of the plug to the other. The pump tool has to provide the necessary pressure to overcome the static pressure of the well fluid above the pump.
An artificial lift tool operates in a harsh or “dirty” environment and pumps well fluid containing contaminants and aggressive fluids. For the tool to be operational in longer periods of time, it is crucial that such contaminants do not accumulate in the pump and that well fluid is prevented from entering vital parts of the pump.